LITHUANIA yesterday became the first former Soviet republic to make a formal request to join Nato. The application was put forward six days before Nato holds a summit in Brussels to discuss closer security arrangements with Eastern Europe.

Lithuania's request was prompted partly by the success in last month's Russian elections of Vladimir Zhirinovsky, the far-right demagogue who has vowed to restore the Soviet empire and abolish the independence of some East European countries. The rise of Mr Zhirinovsky has made Russia's neighbours more determined than ever to seek Nato's protection.

Poland's President, Lech Walesa, said in an interview published yesterday that Nato's reluctance to admit newly democratic East European countries could plunge the region into disaster.

'I won't be satisfied if 50 years from now they say I was right. We kept crying and shouting in 1939, but they only believed us when the war reached Paris and London. The situation is very similar today,' Mr Walesa told the Washington Post.

President Bill Clinton will use the Nato summit to put forward a 'Partnership for Peace' programme that foresees closer ties between the alliance and former Communist countries, but which sets no date for their entry into Nato. John Shalikashvili, chairman of the Joint Chiefs of Staff of the US armed forces, said yesterday that Russia had no veto on East European membership of Nato.

Leaders of Poland, Hungary, the Czech Republic and Slovakia - the so-called Visegrad Four - as well as Romania and Bulgaria believe that this approach is too timid. Hungary's new Prime Minister, Peter Boross, said last month that a security vacuum in central Europe would be dangerous because history showed that the region was vulnerable to the ambitions of outside powers. Czech politicians argued fervently that the Russian election results made Czech membership of Nato essential.

Some Western leaders believe Nato must think carefully before embracing the Visegrad Four because this could play into the hands of Mr Zhirinovsky and other nationalists who oppose an extension of Western influence close to Russia's borders. They want to avoid actions that might appear to isolate Russia or weaken President Boris Yeltsin's domestic position.

However, Mr Yeltsin has sent conflicting signals on Russia's attitude to Nato and Eastern Europe. When visiting Warsaw last August, he said that the days of 'big brother-little brother' relations between Russia and Poland were over. At other times, he has suggested Poland should not join Nato unless Russia is allowed in too. Both Mr Yeltsin and other Russian politicians regarded as 'democrats' in the West have raised the idea of a joint Western-Russian guarantee of Eastern Europe's security.

The Visegrad Four leaders seem certain to tell Mr Clinton, when they meet him in Prague after the Nato summit, that such proposals are unacceptable. For the moment, however, they have little choice but to endorse 'Partnership for Peace' and press for its evolution into a firm Western commitment to their security.

Poland's Foreign Minister, Andrzej Olechowski, has proposed a five-point initiative for developing 'Partnership for Peace'. First, Nato should make clear that it envisages a gradual expansion of the alliance. Second, political and military rules of behaviour should be defined. Third, in the event of a threat to an East European country, Nato should agree to consultations, possibly leading to joint measures to restore peace.

Fourth, Nato's co-operation with individual countries should depend on those countries' democratic progress and observance of military rules of behaviour. Lastly, all East European states should be offered identical forms of co-operation, but any one country should be free to integrate into Nato more quickly than others.

The Visegrad Four fear that if they are not allowed to join Nato and the European Union, they will lose a priceless opportunity to make a reality of their new-found independence. They argue that Russia need not fear isolation if the West includes it in a security and economic dialogue, possibly by admitting Moscow into the G7 group of industrial democracies.

Some Western experts question the sense of admitting countries troubled by ethnic tension, political instability or hostile relations with neighbours. For example, Hungary and Slovakia are at loggerheads over the status of Slovakia's Hungarian minority, and Romania has problems with Hungary and Moldova. Some Nato officials see a risk in extending the doctrine of 'an attack on one is an attack on all' to a region plagued with such rivalries.

WASHINGTON - General

Shalikashvili said an immediate expansion of Nato could have a destabilising impact on Europe, Reuter reports. 'Membership to some and exclusion of others would be counter to what' is in Europe's best interests.